Recording thermometer



Aug. 26, 1958 D. R. BRISTOL RECORDING THERMOMETER Filed June 21, 1954 8 Z 27 5 w M 7 5 6 x 5 5% w .1 3 7 4 In? J 2 w u II 7 H 3 IM W 2 l |l l 5 ll] 5 43 wwu 5 8 0fm 6 W555]. M U 7 W03 3 .ml P

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INVENTOR. Y Donald R. Bristol B M, L4+M United States Patent Ofiiice 2,848,895 RECORDING THERMOMETER Donald R. Bristol, Seattle, Wash, assignor to Ryan Recording Thermometer Company, Seatfle, Wash, a corporation of Washington Application June 21, 1954, Serial No. 438,007 2 Claims. (31. 73-3435 This invention relates to improved means for adjusting the thermostatic elements in a recording thermometer such as that shown in United States PatentNo. 1,989,- 85 6, issued on February 5, 1935. This type of thermometer is commonly used in railway refrigerator cars, refrigerated trucks and trailers, etc., in which perishable food products are transported in order to obtain an accurate record of the temperature maintained during the journey. The thermometer includes thermostatic elements in the form of spiral coils arranged in opposed relation so as to neutralize the vibrations imparted thereto during a journey, in combination with a temperature record sheet, and a stylus cooperating with the record sheet and controlled by the thermostatic elements.

The principal object of the invention is to provide improved means for adjusting the thermostatic elements relatively to each other and to the stylus, so as to insure the operation of the oppositely disposed thermostatic elements in unison, uniform transmission of the movements of said elements to the stylus, and accurate cooperation of the stylus with the recording sheet upon'which the variations in temperature are recorded.

With yet additional objects and advantages in view which, with the foregoing, will appear and be understood in the course of the following description and claims,

the invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

Figure 1 is an enlarged perspective view of one of my thermostatic elements with the parts of the adjusting means therefor shown in exploded relation.

Fig. 2 is a partial central vertical sectional view of a recording thermometer showing the thermostatic elements in operative position and in front elevation.

Fig. 3 is a partial vertical sectional view of the recording thermometer taken on line 33 of Fig. 2.

Fig. 4 is an enlarged fragmentary plan view showing the adjusting means for the right-hand of the thermostatic elements as viewed in Fig. 3, the adjusting means illustrated in Fig. 1 being for the left-hand of the thermostatic elements as viewed in Fig. 3; and

Fig. 5 is a sectional view taken on line 5--5 of Fig. 4.

Figs. 2 and 3 of the drawings correspond to Figs. 1 and 2, respectively, of the aforesaid U. S. Patent No. 1,989,- 856 and for ease of understanding the same identifying numerals have been applied to corresponding structural parts. Accordingly, 22 denotes a cup-shaped member having a cover 28 and centrally divided by a vertical partitioning wall 36 provided by a casing 35. The latter has a top wall 37 of semi-circular shape and at its curved edge this top wall has a downwardly turned flange 38 engaging the interior surface of the vertical annular wall 27 of the member 22.

Positioned within the casing 35 are thermostatic coils 41, 42, each of which is made up of bi-metallic material, one of which, preferably brass, has a high coeflicient of expansion, and the other of which, preferably a nickelsteel alloy, has a coeflicient of expansion which is practically negligible. For supporting the coils there is provided a post 43 which has its outer end threaded to receive a nut 55 and its inner end riveted in a base plate member 46, as at 44. This member 46 is in turn secured to the partition wall 36 by means of securing elements the post 43 is a sleeve 48 which rests plate member by an enlarged annular inner end portion 49. The outer reduced end portion of the sleeve receives a ring 51 and this ring and the enlarged end portion 49 are slotted at 52 and 50, respec tively. Held in these slots by solder are the inner ends of the coils. The ring 51 rests against the shoulder provided by the enlarged portion 49 of the sleeve and its outer end terminates short of the outer end of the sleeve. A washer 53 is rotatably mounted on the post 43 so as to bear against the outer end of the sleeve, such washer being provided with adjusting screws 54 adapted to engage the adjacent end of the ring 51. The nut 55 bears against the Washer when tightened and so it will be evident that by loosening the screw 54, the coil 41 may be rotatively adjusted relative to the other coil 42.

Mounted below and to one side of the coils 41, 42 is a rotatable shaft 56 which extends out through the partition 36 for adjustable connection with a stylus 67. This stylus works on a recording sheet 76 located in a magazine to a spool which is clutch-connected to a shaft 88. A platen 84 gives backing for the recording sheet when it is contacted by the stylus. The shaft 88 passes through The shaft 56 is provided with a collar having a set screw 111 and formed at its ends with a pair of diametrically opposed cranks 57, 58. These cranks are interconnected with the thermostatic coils 41, 42 by links 59, 60 and extensions 161, 162, respectively, which have pin connections with one another, the pins between the links and the extensions being denoted 163, 164. Both of the therare substantially identical and it will be noted from Fig. 1 that the outer end portions thereof are longitudinally slotted at 165. The slots 165, as will be explained shortly, are provided for adjustment purposes and hence their length is of no particular si nifi- D cance other than of being long enough for the desired be considered as a single link having an effective length equal to the distance between the axis of the post 43 and manner the coil 42 and extension 162 can be considered as a single component of a three bar linkage having a link 60 and crank 58 as its other two components. If both of these three bar linkages were identical in length, the cranks 57, 58 would be subjected to the same turning movements by a change in temperature, assuming, of

Patented Aug. 26, 1958 t as-will be apparent 'Fromfig S'is can be noted ears bend at right angles to. bear against the wall 27.

have equal expansion rates and that the components of the linkages were initially set with the same angular relationship .with one another. This first assumption is taken care of by way of the fact that the length of each coil. between its inner end and itskc'o'nnecting point with- 1 the respective extensioncan be accurately adjusted by: the], However, the second assumption re the angular relationshipof the com the present instancefrom an examination of Fig. 2.- For. will be noted that the angle between the screw 166 and slot 165 arrangement.

ponents of the linkages is nottrue in example, it

crank 58 and link 60 is less than the, angle between the crank 57 and link 59 Accordingly,

the parts of the link-y mas-ass ofthe'coils', with the recording.v sheet. formed by turning the agesiare so formed that the pin 164 is always slightly l closer to the axis of the post 43 than is the pin 163, and this compensates for the variance in the angles betweenrespective components of thelinkages.

It is important that the extensions 161-, 162 be heldsecurely against movements relative to the coils after they have'b'een adjusted, and accordingly, the nuts 167 v are f ormed witli'reduced flat-sided heads 168 correspond-- .ing in width to that of the grooves 165 so as to nest therein and thereby'be restrained against rotation.- Turn- 7 ing of the extensions about the'screws 166 is prevented by ofiset'flat-sided; tongues 171 which mate with the grooves 165m similar manner to the nut heads 168. that the tongues 171 are drawn against-the nuts 168 as the screws 166 are tightenedand may be slightly deformed to load the screws. Both extensions provide a pairof spaced parallel ears 172 serving as gudgeons for the p to and from the free ends of tapered body portions 173, thattheextensions differ. The portion 173 of cxten-t' sion'161 is flat whereas theportion 17 A of extension162 curves out of the plane of the rest of the extension as seen in Fig. 5 and also curves to one sideof the related j coil42'so that thet link 60 can clear the side of the coil as best shown in: Fig. 3.

The adjustmentof the device will now be explained.

To coordinate .the coils and their linkages with the stylus:

67, theset screw 111 on the collar 110 is loosened and the. coils, after being positioned around the post43, are

pins 163, 164. These 174 and it is in these portions turned with respect theretountil the crank 58 is brought The stylus and shaft 56-are" thenturnedwith respect to the collar to bringithe stylus:

point at .the upper end of the recording sheet 76 and the set screw 111 is tightened; 'As a second adjustment step" the extensions 1 61, .162 are. adjusted along the slots 165 in the 'coils by use of the screws 166 to give the stylus the correct amount of movement with regard to the scale of thelreeording sheet fora giventemperature change. Following this step thecoils' 41,- 42 are turned with respectito the post 43 until the stylus reads on the ambient temperature and the nut is tightened thus completing. the

The final, adjusting step is percoil 42 and the post 43 to eliminate any lag in the system and then the screws 54 are tightened.

The advantages of the invention, it is thought, will have been clearly understood 'fromthe toregolng detailed description of the illustrated preferred embodiment. changes will suggest-themselves and may be" resorted to 7 Minor without departing from the spirit of the invention, wheretore his my'interition that no'limitations be implied and that the hereto annexed claimsbe given-a scope fully commensurate with the broadest interpretation to which the employed-language admits} What I claim is:

1. In a recordihgthermbm'et'er, apairo'f thermostatic coils having their inner ends fixed with respect to a given common axis central of "coils havingarflthifer Grid portib radius of curvatul which hasa constant th refereii calibration temperature 'and =whieh -ifs formed with a said niean's comprising '.'a' membe' the' respe'ctive said link and hav-m screw passing throughsaid hol adjustably connecting the other ends of r'id the re'spe ctive slot,

and a nut on s'aid screw extending ihto' the' slot by" a reduCed hea'd havirlg diametrically opposite flat-side edge portions arranged and'a'dapted to be' rm'trainedf'rom turnings'and from shiftingsideways in the 1 slot bythe side' walls= thereof whereby said In in'br" is -adju'st'ably Iconnectd to the slotted poi'tionof -ft-he respective-coil.

2; The structule of claim- 1 in whicheach ofs'aid rnernhers is formed with anofise't to'n'gue 'whichextends' therefronfinto' said slot"ofihe respective coil ,'-h' as a' width substantiallyth'at of the slog-and is arrangedto bear against the respective said nut-1 when the 'corfes'pondin g screw 1s tightened ata selected point along 'the -lngth of the='slot.'

References Cited the file of-this' pateiit UNITED srfArhsrArENrs' Barstow .-Apr." 1,1930 Frant-z Feb; 5, 1935 McGabe June 23, 1942 FORE GN "PATENTS I their linkages, and the stylus coil 41 with respect to the other the coils, each of said,

to 'said axis at a given espective means for 

